Identification Of Selected Inputs - Emerson Fisher Fieldvue DVC6030f Instruction Manual

be "Good," "Good_Cascade," or "Uncertain" with a
STATUS_OPTS [10] of "Use Uncertain as Good" in
order to be evaluated. If the status of OP_SELECT
[22] is Bad, then the OUT [7] status is Bad.

Identification of Selected Inputs

For a SELECT_TYPE [19] of Maximum, Minimum,
Middle, First Good, and Hot Spare, SELECTED [21]
indicates the number of the selected input. When
Middle is computed from more than one input,
SELECTED [21] is set to 0.
For a SELECT_TYPE [19] of Average, SELECTED
[21] indicates the number of inputs used in the
average calculation.
When the block mode is Manual, SELECTED [21] is
set to 0.
Alarm Detection
A block alarm will be generated whenever the
BLOCK_ERR [6] has an error bit set. The types of
block error for the PID block are defined above.
Process alarm detection is based on OUT [7] value.
You can configure the alarm limits of the following
standard alarms:
D High (HI_LIM [40])
D High high (HI_HI_LIM [38])
D Low (LO_LIM [42])
D Low low (LO_LO_LIM [44])
In order to avoid alarm chattering when the variable is
oscillating around the alarm limit, an alarm hysteresis
in percent of the PV span can be set using the
ALARM_HYS [36] parameter. The priority of each
alarm is set in the following parameters:
D HI_PRI [39]
D HI_HI_PRI [37]
D LO_PRI [41]
D LO_LO_PRI [43]
ACK_OPTION [35] is used to set automatic
acknowledgement of alarms.
ALARM_SUM [34] indicates the current alert status,
unacknowledged states, and disabled states of the
alarms associated with the function block.
March 2006
ISEL Function Block
Alarms are grouped into five levels of priority, as
shown in table 5-37.
Table 5-37. ISEL Function Block Alarm Priorities
Priority
Priority Description
Number
The priority of an alarm condition changes to 0 after the
0
condition that caused the alarm is corrected.
An alarm condition with a priority of 1 can be recognized
1 by the system. The device monitors the alarm but does
not report it until requested by the host system.
An alarm condition with a priority of 2 is reported to the
2 operator, but generally does not require operator attention
(such as diagnostics and system alerts).
Alarm conditions of priority 3 to 7 are advisory alarms of
3−7
increasing priority.
Alarm conditions of priority 8 to 15 are critical alarms of
8−15
increasing priority.
1. The priority classes "advise" and critical" have no relationship to Plant Web Alerts.
Block Errors
Table 5-38 lists conditions reported in the
BLOCK_ERR [6] parameter. Conditions in italics are
not applicable for the ISEL block and are provided only
for your reference.
Table 5-38. BLOCK_ERR Conditions
Condition
Condition Name and Description
Number
0 Other (N/A)
Block Configuration Error - If OP_SELECT is not being
1 used, and SELECT_TYPE = 0. This implies OP_SELECT
status is good and actual mode is AUTO.
2 Link Configuration Error (N/A)
3 Simulate Active (N/A)
4 Local Override (N/A)
5 Device Fault State Set (N/A)
6 Device Needs Maintenance Soon (N/A)
Input failure/process variable has Bad status - Set if any
IN or any DISABLE or OP_SELECT is bad and connected.
This means that a status of BAD NC would not cause an
7
input failure but a status of BAD LUV or BAD no LUV would
cause and input failure.
Output failure - Set if OUT quality is bad and the Actual
8
mode is not Out of Service.
9 Memory Failure (N/A)
10 Lost Static Data (N/A)
11 Lost NV Data (N/A)
12 Readback Check Failed (N/A)
13 Device Needs Maintenance Now (N/A)
Power Up - Set if the Target mode is Out of Service when
14
powered up until the mode is changed.
15 Out of Service - The block is in Out of Service (O/S) mode.
(1)
5
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